A microneedle device provided with fine needles (microneedles) is effective as a less-invasive percutaneous medicinal solution delivery device. However, since the microneedle has a fine needle structure, the manufacturing and handling thereof is difficult as compared with a conventional injection needle.
In particular, with regard to a hollow-shaped microneedle having a flow channel formed therein likewise the structure of the conventional injection needle, because of its fine structure, the manufacturing thereof is difficult, and further, the connection thereof with solution delivery means for delivering a medicinal solution to be injected, such as a syringe, a tube or a pump, is also difficult.
Therefore, the applicant of the present invention has filed a patent application for a jig for microneedle array placement and a microneedle array device as disclosed in Patent Document 1, of which structure will be explained briefly as below:
First, there is a plurality of microneedle units provided with a plurality of microneedles, respectively, and this plurality of microneedle units is integrated by a needle holder (for example, made of rubber), and is accommodated in a case comprising an upper case and a lower case. With regard to the microneedle unit, flow channel bosses formed in the microneedle unit are inserted with pressure into medicinal solution distribution holes formed in the needle holder, so as to be connected to the needle holder.
Moreover, a medicinal solution inlet is formed in the lower case, and the medicinal solution inlet is communicating with the flow channels of the all microneedle units. Thus, a medicinal solution inlet is connected, via a tube, etc., to a pump, etc., and the medicinal solution is supplied, via the tube and the medicinal solution inlet, to the microneedle units, and eventually to the microneedles.
Moreover, there are other inventions as disclosed in Patent Document 2 and Patent Document 3.
With regard to a medicinal solution container and a medicinal solution injection device as described in Patent Document 2, a needle tube having needles at the both ends (double-headed needle) is provided, and one end of the needle tube penetrates a seal member to be immersed in a medicinal solution container filled with a medicinal solution, and the other end of the needle tube discharges the medicinal solution into the skin. As compared with the structure of Patent Document 1, the structure of Patent Document 2 has a simpler structure with a less number of component parts, and since the needle tube penetrates the seal member to be immersed in the medicinal solution container, the risk of leakage of medicinal solution is low.
Moreover, with regard to a pre-filled syringe as described in Patent Document 3, a double-headed needle is provided similarly, so that one end of the double-headed needle penetrates a seal body to be immersed in the medicinal solution container, and the other end of the double-headed needle discharges the medicinal solution into the skin. Also in this case, as compared with the structure of Patent Document 1, the structure is simpler with a less number of component parts, and since the one end of the double-headed needle penetrates the seal body to be immersed in the medicinal solution container, the risk of leakage of medicinal solution is low.